1. Field of the Invention
The present invention relates to a photo printer in which an image is recorded onto a photosensitive recording material loaded in a loading chamber. More particularly, the present invention relates to a photo printer capable of preventing the loading chamber from being opened while the recording material is loaded herein.
2. Background Arts
An electronic still camera having a printing device is disclosed in Japanese Patent Laid-Open Publication No. 11-127409, in which a photo printer and a mono-sheet type instant film are used as a printing device and a recording material, respectively. Compared to a thermal printer such as a thermal transfer printer or a thermal sublimation printer, the photo printer consume so less electricity as to be driven by internal batteries. Accordingly, the photo printer has the advantage of portability. Moreover, compared to an inkjet printer, which is necessary to manage inks, the photo printer has the advantage to work without maintenance.
In the photo printer, like an ordinary instant camera, a film pack is used as a basic unit for handling the instant films. The film pack is loaded inside a pack loading chamber provided in the electronic still camera. The pack loading chamber is kept in light-tight fashion, by closing a pack loading door that is used as a cover. The instant film is exposed to printing light projected from a printing head, latent image is formed on the instant film. After an exposure, the instant film is ejected through a pair of spread rollers. During ejection, a positive image is developed.
The electronic still camera converts an optical image of a subject to an electric image signal through a CCD image sensor or the like, convert the image signal to digital image data, which is written in an image memory. Since an exposure is started by selecting image data from the image memory, it is possible to carry out taking a subject even if a film pack is unloaded. Compared to an ordinary instant camera, an user of the electronic still camera is less aware whether the film pack is loaded, or of the remaining number of available instant films. Therefore, there is possibility that the pack loading chamber is opened by mistake while an unexposed instant film is loaded inside the pack loading chamber.
In view of the foregoing, an object of the present invention is to provide a photo printer for preventing a pack loading chamber from being opened while an instant film is loaded herein.
Another object of the present invention is to provide a photo printer in which a pack loading door for opening the pack loading chamber is moved by a simple structure and at a low cost.
To achieve the above objects, a printer of the present invention is comprised of counting means for counting remaining number that represents an amount of the instant film left inside the pack loading chamber, and control means for checking the remaining number and prohibiting the pack loading door from being open when the remaining number is equal to or more than one. The photo printer has a operation member that is operated externally for opening the pack loading chamber. When the operation member is operated over a predetermined time continuously, the control means checks the remaining number.
The counting means subscribes the remaining number by one each time the instant film is ejected outside of the photo printer, and sets the remaining number for an initial value when the film pack is loaded inside the pack loading chamber.
In the preferable embodiment of the present invention, the photo printer has a door moving mechanism that is comprised of a lock lever and a rotating lever. The lock lever is movable between a keep position for locking the pack loading chamber and a release position for releasing the lock of the pack loading chamber. The rotating lever pushes the lock lever toward the release position when rotating forward and retracts from the lock lever when rotating inversely.
The photo printer has driving means that is comprised of a feeding motor for feeding the instant film toward outside of the photo printer, a primary gear for transmitting rotation of the feeding motor to the rotating lever, and a secondary gear for transmitting rotation of the primary gear to developing means. The primary gear rotates the rotating lever inversely when the feeding motor rotates in a first direction, and rotates the rotating lever forward when the feeding motor rotates in a second direction.
The photo printer has delay transmitting means that is comprised of a pin attached to the primary gear and a groove provided in the secondary gear. Rotation of the primary gear is not transmitted to the secondary gear while the pin moves along the groove.
According to the present invention, since the pack loading door is not open when the instant film is left inside the pack loading chamber, an unexposed instant film is never exposed to outside light by mistake.
Moreover, since the door moving mechanism is actuated by the feeding motor for actuating the developing means, the printer of the present invention makes it possible to improve its function by a simple structure and at a low cost.